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Yang X, Zeng Q, İnam MG, İnam O, Lin CS, Tezel G. cFLIP in the molecular regulation of astroglia-driven neuroinflammation in experimental glaucoma. J Neuroinflammation 2024; 21:145. [PMID: 38824526 PMCID: PMC11143607 DOI: 10.1186/s12974-024-03141-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Accepted: 05/24/2024] [Indexed: 06/03/2024] Open
Abstract
BACKGROUND Recent experimental studies of neuroinflammation in glaucoma pointed to cFLIP as a molecular switch for cell fate decisions, mainly regulating cell type-specific caspase-8 functions in cell death and inflammation. This study aimed to determine the importance of cFLIP for regulating astroglia-driven neuroinflammation in experimental glaucoma by analyzing the outcomes of astroglia-targeted transgenic deletion of cFLIP or cFLIPL. METHODS Glaucoma was modeled by anterior chamber microbead injections to induce ocular hypertension in mouse lines with or without conditional deletion of cFLIP or cFLIPL in astroglia. Morphological analysis of astroglia responses assessed quantitative parameters in retinal whole mounts immunolabeled for GFAP and inflammatory molecules or assayed for TUNEL. The molecular analysis included 36-plexed immunoassays of the retina and optic nerve cytokines and chemokines, NanoString-based profiling of inflammation-related gene expression, and Western blot analysis of selected proteins in freshly isolated samples of astroglia. RESULTS Immunoassays and immunolabeling of retina and optic nerve tissues presented reduced production of various proinflammatory cytokines, including TNFα, in GFAP/cFLIP and GFAP/cFLIPL relative to controls at 12 weeks of ocular hypertension with no detectable alteration in TUNEL. Besides presenting a similar trend of the proinflammatory versus anti-inflammatory molecules displayed by immunoassays, NanoString-based molecular profiling detected downregulated NF-κB/RelA and upregulated RelB expression of astroglia in ocular hypertensive samples of GFAP/cFLIP compared to ocular hypertensive controls. Analysis of protein expression also revealed decreased phospho-RelA and increased phospho-RelB in parallel with an increase in caspase-8 cleavage products. CONCLUSIONS A prominent response limiting neuroinflammation in ocular hypertensive eyes with cFLIP-deletion in astroglia values the role of cFLIP in the molecular regulation of glia-driven neuroinflammation during glaucomatous neurodegeneration. The molecular responses accompanying the lessening of neurodegenerative inflammation also seem to maintain astroglia survival despite increased caspase-8 cleavage with cFLIP deletion. A transcriptional autoregulatory response, dampening RelA but boosting RelB for selective expression of NF-κB target genes, might reinforce cell survival in cFLIP-deleted astroglia.
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Affiliation(s)
- Xiangjun Yang
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Qun Zeng
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Maide Gözde İnam
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Onur İnam
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
| | - Chyuan-Sheng Lin
- Department of Pathology & Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Gülgün Tezel
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA.
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Mahmud I, Tian G, Wang J, Hutchinson TE, Kim BJ, Awasthee N, Hale S, Meng C, Moore A, Zhao L, Lewis JE, Waddell A, Wu S, Steger JM, Lydon ML, Chait A, Zhao LY, Ding H, Li JL, Purayil HT, Huo Z, Daaka Y, Garrett TJ, Liao D. DAXX drives de novo lipogenesis and contributes to tumorigenesis. Nat Commun 2023; 14:1927. [PMID: 37045819 PMCID: PMC10097704 DOI: 10.1038/s41467-023-37501-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 03/20/2023] [Indexed: 04/14/2023] Open
Abstract
Cancer cells exhibit elevated lipid synthesis. In breast and other cancer types, genes involved in lipid production are highly upregulated, but the mechanisms that control their expression remain poorly understood. Using integrated transcriptomic, lipidomic, and molecular studies, here we report that DAXX is a regulator of oncogenic lipogenesis. DAXX depletion attenuates, while its overexpression enhances, lipogenic gene expression, lipogenesis, and tumor growth. Mechanistically, DAXX interacts with SREBP1 and SREBP2 and activates SREBP-mediated transcription. DAXX associates with lipogenic gene promoters through SREBPs. Underscoring the critical roles for the DAXX-SREBP interaction for lipogenesis, SREBP2 knockdown attenuates tumor growth in cells with DAXX overexpression, and DAXX mutants unable to bind SREBP1/2 have weakened activity in promoting lipogenesis and tumor growth. Remarkably, a DAXX mutant deficient of SUMO-binding fails to activate SREBP1/2 and lipogenesis due to impaired SREBP binding and chromatin recruitment and is defective of stimulating tumorigenesis. Hence, DAXX's SUMO-binding activity is critical to oncogenic lipogenesis. Notably, a peptide corresponding to DAXX's C-terminal SUMO-interacting motif (SIM2) is cell-membrane permeable, disrupts the DAXX-SREBP1/2 interactions, and inhibits lipogenesis and tumor growth. These results establish DAXX as a regulator of lipogenesis and a potential therapeutic target for cancer therapy.
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Affiliation(s)
- Iqbal Mahmud
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
- Southeast Center for Integrated Metabolomics, Clinical and Translational Science Institute, University of Florida, Gainesville, FL, USA
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL, USA
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Guimei Tian
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Jia Wang
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
- The Affiliated Cancer Hospital of Zhengzhou University & Henan Cancer Hospital, 450008, Zhengzhou, Henan, China
| | - Tarun E Hutchinson
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Brandon J Kim
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Nikee Awasthee
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Seth Hale
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Chengcheng Meng
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Allison Moore
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Liming Zhao
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Jessica E Lewis
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Aaron Waddell
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Shangtao Wu
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Julia M Steger
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - McKenzie L Lydon
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Aaron Chait
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Lisa Y Zhao
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
- Department of Medicine, University of Florida College of Medicine, Gainesville, FL, USA
| | - Haocheng Ding
- Department of Biostatistics, University of Florida, Gainesville, FL, USA
| | - Jian-Liang Li
- Integrative Bioinformatics, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Hamsa Thayele Purayil
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Zhiguang Huo
- Department of Biostatistics, University of Florida, Gainesville, FL, USA
| | - Yehia Daaka
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Timothy J Garrett
- Southeast Center for Integrated Metabolomics, Clinical and Translational Science Institute, University of Florida, Gainesville, FL, USA
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL, USA
| | - Daiqing Liao
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, Gainesville, FL, USA.
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do Nascimento Gonçalves N, Caldas HC, da Silva Florim GM, Sormani GM, Arantes LMRB, Sorroche BP, Baptista MASF, Fernandes-Charpiot IMM, Nascimento-Filho CHV, de Castilho RM, Abbud-Filho M. Distinct global DNA methylation and NF-κB expression profile of preimplantation biopsies from ideal and non-ideal kidneys. J Nephrol 2022; 35:1831-1840. [PMID: 35524842 DOI: 10.1007/s40620-022-01341-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 04/20/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND Epigenetic mechanisms may affect the ideal and non-ideal kidneys selected for transplantation and their inflammatory gene expression profile differently and may contribute to poor clinical outcomes. OBJECTIVE Study the Global DNA methylation and the expression profiles of the DNA methyltransferases (DNMTs) and nuclear factor kappa B (NF-κB) in preimplantation kidney biopsies from ideal and non-ideal kidneys (expanded criteria donor (ECD) and with KDPI > 85%). METHODS In a sample consisting of 45 consecutive pre-implantation biopsies, global DNA methylation levels were detected by LINE-1 repeated elements using bisulfite pyrosequencing. DNMT gene expression was assessed by real-time quantitative polymerase chain reaction, and NF-κB protein expression by immunofluorescence. RESULTS ECD kidneys displayed increased methylation levels in LINE-1, and DNMT1 and DNMT3B expression was upregulated when comparing ECD to standard criteria donor kidneys. Similarly, kidneys with KDPI > 85% exhibited increased LINE-1 methylation and DNMT1 upregulation when compared to a KDPI ≤ 85%. NF-κB protein expression levels were greatly increased in both types of non-ideal kidneys compared to ideal kidneys. Moreover, hypermethylation of LINE-1 was associated with cold ischemia time > 20 h and ECD kidney classification. CONCLUSIONS This study shows that global DNA hypermethylation and high expression of NF-κB occurred in both types of non-ideal kidneys and were associated with prolonged cold ischemia time. Global DNA methylation can be a useful tool to assess non-ideal kidneys and hence, could be used to expand the pool of kidneys donors.
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Affiliation(s)
- Naiane do Nascimento Gonçalves
- Department of Medicine, Faculdade de Medicina de São José do Rio Preto (FAMERP), Laboratório de Imunologia e Transplante Experimental (LITEX), Hospital de Base, Av. Brigadeiro Faria Lima, 5416, São Jose do Rio Preto, SP, 15090-000, Brazil
| | - Heloisa Cristina Caldas
- Department of Medicine, Faculdade de Medicina de São José do Rio Preto (FAMERP), Laboratório de Imunologia e Transplante Experimental (LITEX), Hospital de Base, Av. Brigadeiro Faria Lima, 5416, São Jose do Rio Preto, SP, 15090-000, Brazil
| | - Greiciane Maria da Silva Florim
- Department of Medicine, Faculdade de Medicina de São José do Rio Preto (FAMERP), Laboratório de Imunologia e Transplante Experimental (LITEX), Hospital de Base, Av. Brigadeiro Faria Lima, 5416, São Jose do Rio Preto, SP, 15090-000, Brazil
| | - Giovanna Mattiello Sormani
- Department of Medicine, Faculdade de Medicina de São José do Rio Preto (FAMERP), Laboratório de Imunologia e Transplante Experimental (LITEX), Hospital de Base, Av. Brigadeiro Faria Lima, 5416, São Jose do Rio Preto, SP, 15090-000, Brazil
| | | | | | - Maria Alice Sperto Ferreira Baptista
- Department of Medicine, Faculdade de Medicina de São José do Rio Preto (FAMERP), Laboratório de Imunologia e Transplante Experimental (LITEX), Hospital de Base, Av. Brigadeiro Faria Lima, 5416, São Jose do Rio Preto, SP, 15090-000, Brazil
| | - Ida Maria Maximina Fernandes-Charpiot
- Department of Medicine, Faculdade de Medicina de São José do Rio Preto (FAMERP), Laboratório de Imunologia e Transplante Experimental (LITEX), Hospital de Base, Av. Brigadeiro Faria Lima, 5416, São Jose do Rio Preto, SP, 15090-000, Brazil
| | | | - Rogério Moraes de Castilho
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Mario Abbud-Filho
- Department of Medicine, Faculdade de Medicina de São José do Rio Preto (FAMERP), Laboratório de Imunologia e Transplante Experimental (LITEX), Hospital de Base, Av. Brigadeiro Faria Lima, 5416, São Jose do Rio Preto, SP, 15090-000, Brazil.
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Impact of Chromatin Dynamics and DNA Repair on Genomic Stability and Treatment Resistance in Pediatric High-Grade Gliomas. Cancers (Basel) 2021; 13:cancers13225678. [PMID: 34830833 PMCID: PMC8616465 DOI: 10.3390/cancers13225678] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/08/2021] [Accepted: 11/11/2021] [Indexed: 02/07/2023] Open
Abstract
Simple Summary Pediatric high-grade gliomas (pHGGs) are the leading cause of mortality in pediatric neuro-oncology, due in great part to treatment resistance driven by complex DNA repair mechanisms. pHGGs have recently been divided into molecular subtypes based on mutations affecting the N-terminal tail of the histone variant H3.3 and the ATRX/DAXX histone chaperone that deposits H3.3 at repetitive heterochromatin loci that are of paramount importance to the stability of our genome. This review addresses the functions of H3.3 and ATRX/DAXX in chromatin dynamics and DNA repair, as well as the impact of mutations affecting H3.3/ATRX/DAXX on treatment resistance and how the vulnerabilities they expose could foster novel therapeutic strategies. Abstract Despite their low incidence, pediatric high-grade gliomas (pHGGs), including diffuse intrinsic pontine gliomas (DIPGs), are the leading cause of mortality in pediatric neuro-oncology. Recurrent, mutually exclusive mutations affecting K27 (K27M) and G34 (G34R/V) in the N-terminal tail of histones H3.3 and H3.1 act as key biological drivers of pHGGs. Notably, mutations in H3.3 are frequently associated with mutations affecting ATRX and DAXX, which encode a chaperone complex that deposits H3.3 into heterochromatic regions, including telomeres. The K27M and G34R/V mutations lead to distinct epigenetic reprogramming, telomere maintenance mechanisms, and oncogenesis scenarios, resulting in distinct subgroups of patients characterized by differences in tumor localization, clinical outcome, as well as concurrent epigenetic and genetic alterations. Contrasting with our understanding of the molecular biology of pHGGs, there has been little improvement in the treatment of pHGGs, with the current mainstays of therapy—genotoxic chemotherapy and ionizing radiation (IR)—facing the development of tumor resistance driven by complex DNA repair pathways. Chromatin and nucleosome dynamics constitute important modulators of the DNA damage response (DDR). Here, we summarize the major DNA repair pathways that contribute to resistance to current DNA damaging agent-based therapeutic strategies and describe the telomere maintenance mechanisms encountered in pHGGs. We then review the functions of H3.3 and its chaperones in chromatin dynamics and DNA repair, as well as examining the impact of their mutation/alteration on these processes. Finally, we discuss potential strategies targeting DNA repair and epigenetic mechanisms as well as telomere maintenance mechanisms, to improve the treatment of pHGGs.
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Takahashi M, Lio CWJ, Campeau A, Steger M, Ay F, Mann M, Gonzalez DJ, Jain M, Sharma S. The tumor suppressor kinase DAPK3 drives tumor-intrinsic immunity through the STING-IFN-β pathway. Nat Immunol 2021; 22:485-496. [PMID: 33767426 PMCID: PMC8300883 DOI: 10.1038/s41590-021-00896-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 02/05/2021] [Indexed: 01/31/2023]
Abstract
Evasion of host immunity is a hallmark of cancer; however, mechanisms linking oncogenic mutations and immune escape are incompletely understood. Through loss-of-function screening of 1,001 tumor suppressor genes, we identified death-associated protein kinase 3 (DAPK3) as a previously unrecognized driver of anti-tumor immunity through the stimulator of interferon genes (STING) pathway of cytosolic DNA sensing. Loss of DAPK3 expression or kinase activity impaired STING activation and interferon (IFN)-β-stimulated gene induction. DAPK3 deficiency in IFN-β-producing tumors drove rapid growth and reduced infiltration of CD103+CD8α+ dendritic cells and cytotoxic lymphocytes, attenuating the response to cancer chemo-immunotherapy. Mechanistically, DAPK3 coordinated post-translational modification of STING. In unstimulated cells, DAPK3 inhibited STING K48-linked poly-ubiquitination and proteasome-mediated degradation. After cGAMP stimulation, DAPK3 was required for STING K63-linked poly-ubiquitination and STING-TANK-binding kinase 1 interaction. Comprehensive phospho-proteomics uncovered a DAPK3-specific phospho-site on the E3 ligase LMO7, critical for LMO7-STING interaction and STING K63-linked poly-ubiquitination. Thus, DAPK3 is an essential kinase for STING activation that drives tumor-intrinsic innate immunity and tumor immune surveillance.
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Affiliation(s)
| | - Chan-Wang J Lio
- La Jolla Institute for Immunology, La Jolla, CA, USA
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Anaamika Campeau
- Department of Pharmacology, University of California, San Diego, San Diego, CA, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, San Diego, CA, USA
| | - Martin Steger
- Max Planck Institute of Biochemistry, Martinsried, Germany
- Evotec München GmbH, Martinsried, Germany
| | - Ferhat Ay
- La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Matthias Mann
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - David J Gonzalez
- Department of Pharmacology, University of California, San Diego, San Diego, CA, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, San Diego, CA, USA
| | - Mohit Jain
- Department of Pharmacology, University of California, San Diego, San Diego, CA, USA
- Department of Medicine, University of California, San Diego, San Diego, CA, USA
| | - Sonia Sharma
- La Jolla Institute for Immunology, La Jolla, CA, USA.
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Chen D, Zhou XZ, Lee TH. Death-Associated Protein Kinase 1 as a Promising Drug Target in Cancer and Alzheimer's Disease. Recent Pat Anticancer Drug Discov 2020; 14:144-157. [PMID: 30569876 PMCID: PMC6751350 DOI: 10.2174/1574892814666181218170257] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/23/2018] [Accepted: 12/13/2018] [Indexed: 02/06/2023]
Abstract
Background: Death-Associated Protein Kinase 1 (DAPK1) plays an important role in apopto-sis, tumor suppression and neurodegeneration including Alzheimer’s Disease (AD). Objective: This review will describe the diverse roles of DAPK1 in the development of cancer and AD, and the current status of drug development targeting DAPK1-based therapies. Methods: Reports of DAPK1 regulation, function and substrates were analyzed using genetic DAPK1 manipulation and chemical DAPK1 modulators. Results: DAPK1 expression and activity are deregulated in cancer and AD. It is down-regulated and/or inactivated by multiple mechanisms in many human cancers, and elicits a protective effect to counteract numerous death stimuli in cancer, including activation of the master regulator Pin1. Moreover, loss of DAPK1 expression has correlated strongly with tumor recurrence and metastasis, suggesting that lack of sufficient functional DAPK1 might contribute to cancer. In contrast, DAPK1 is highly expressed in the brains of most human AD patients and has been identified as one of the genetic factors affecting suscepti-bility to late-onset AD. The absence of DAPK1 promotes efficient learning and better memory in mice and prevents the development of AD by acting on many key proteins including Pin1 and its downstream tar-gets tau and APP. Recent patents show that DAPK1 modulation might be used to treat both cancer and AD. Conclusion: DAPK1 plays a critical role in diverse physiological processes and importantly, its deregula-tion is implicated in the pathogenesis of either cancer or AD. Therefore, manipulating DAPK1 activity and/or expression may be a promising therapeutic option for cancer or AD.
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Affiliation(s)
- Dongmei Chen
- Fujian Key Laboratory for Translational Research in Cancer and Neurodegenerative Diseases, Institute for Translational Medicine, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian 350122, China
| | - Xiao Z Zhou
- Division of Translational Therapeutics, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, United States
| | - Tae H Lee
- Fujian Key Laboratory for Translational Research in Cancer and Neurodegenerative Diseases, Institute for Translational Medicine, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian 350122, China
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Abstract
The tumor suppressor phosphatase and tension homolog (PTEN) is frequently mutated in human cancers, and it functions in multiple ways to safeguard cells from tumorigenesis. In the cytoplasm, PTEN antagonizes the PI3K/AKT pathway and suppresses cellular proliferation and survival. In the nucleus, PTEN is indispensable for the maintenance of genomic stability. In addition, PTEN loss leads to extensive changes in gene expression at the transcriptional level. The linker histone H1, generally considered as a transcriptional repressor, binds to the nucleosome to form a structure named the chromatosome. The dynamics between H1 and chromatin play an important role in determining gene expression. Here, we summarize the current understanding of roles of PTEN in controlling chromatin dynamics and global gene expression, which is crucial function of nuclear PTEN. We will also introduce the recent discovery of the PTEN family members and their functions.
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Affiliation(s)
- Jingyi Yang
- Institute of Systems Biomedicine, Beijing Key Laboratory of Tumor Systems Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yuxin Yin
- Institute of Systems Biomedicine, Beijing Key Laboratory of Tumor Systems Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.,Peking-Tsinghua Center for Life Sciences, Peking University Health Science Center, Beijing 100191, China
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Epigenetic Control of Autophagy in Cancer Cells: A Key Process for Cancer-Related Phenotypes. Cells 2019; 8:cells8121656. [PMID: 31861179 PMCID: PMC6952790 DOI: 10.3390/cells8121656] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/19/2019] [Accepted: 12/13/2019] [Indexed: 02/06/2023] Open
Abstract
Although autophagy is a well-known and extensively described cell pathway, numerous studies have been recently interested in studying the importance of its regulation at different molecular levels, including the translational and post-translational levels. Therefore, this review focuses on the links between autophagy and epigenetics in cancer and summarizes the. following: (i) how ATG genes are regulated by epigenetics, including DNA methylation and post-translational histone modifications; (ii) how epidrugs are able to modulate autophagy in cancer and to alter cancer-related phenotypes (proliferation, migration, invasion, tumorigenesis, etc.) and; (iii) how epigenetic enzymes can also regulate autophagy at the protein level. One noteable observation was that researchers most often reported conclusions about the regulation of the autophagy flux, following the use of epidrugs, based only on the analysis of LC3B-II form in treated cells. However, it is now widely accepted that an increase in LC3B-II form could be the consequence of an induction of the autophagy flux, as well as a block in the autophagosome-lysosome fusion. Therefore, in our review, all the published results describing a link between epidrugs and autophagy were systematically reanalyzed to determine whether autophagy flux was indeed increased, or inhibited, following the use of these potentially new interesting treatments targeting the autophagy process. Altogether, these recent data strongly support the idea that the determination of autophagy status could be crucial for future anticancer therapies. Indeed, the use of a combination of epidrugs and autophagy inhibitors could be beneficial for some cancer patients, whereas, in other cases, an increase of autophagy, which is frequently observed following the use of epidrugs, could lead to increased autophagy cell death.
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Mahmud I, Liao D. DAXX in cancer: phenomena, processes, mechanisms and regulation. Nucleic Acids Res 2019; 47:7734-7752. [PMID: 31350900 PMCID: PMC6735914 DOI: 10.1093/nar/gkz634] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/05/2019] [Accepted: 07/12/2019] [Indexed: 12/13/2022] Open
Abstract
DAXX displays complex biological functions. Remarkably, DAXX overexpression is a common feature in diverse cancers, which correlates with tumorigenesis, disease progression and treatment resistance. Structurally, DAXX is modular with an N-terminal helical bundle, a docking site for many DAXX interactors (e.g. p53 and ATRX). DAXX's central region folds with the H3.3/H4 dimer, providing a H3.3-specific chaperoning function. DAXX has two functionally critical SUMO-interacting motifs. These modules are connected by disordered regions. DAXX's structural features provide a framework for deciphering how DAXX mechanistically imparts its functions and how its activity is regulated. DAXX modulates transcription through binding to transcription factors, epigenetic modifiers, and chromatin remodelers. DAXX's localization in the PML nuclear bodies also plays roles in transcriptional regulation. DAXX-regulated genes are likely important effectors of its biological functions. Deposition of H3.3 and its interactions with epigenetic modifiers are likely key events for DAXX to regulate transcription, DNA repair, and viral infection. Interactions between DAXX and its partners directly impact apoptosis and cell signaling. DAXX's activity is regulated by posttranslational modifications and ubiquitin-dependent degradation. Notably, the tumor suppressor SPOP promotes DAXX degradation in phase-separated droplets. We summarize here our current understanding of DAXX's complex functions with a focus on how it promotes oncogenesis.
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Affiliation(s)
- Iqbal Mahmud
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, 1333 Center Drive, Gainesville, FL 32610-0235, USA
| | - Daiqing Liao
- Department of Anatomy and Cell Biology, UF Health Cancer Center, University of Florida College of Medicine, 1333 Center Drive, Gainesville, FL 32610-0235, USA
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Khatami F, Larijani B, Heshmat R, Nasiri S, Saffar H, Shafiee G, Mossafa A, Tavangar SM. Promoter Methylation of Four Tumor Suppressor Genes in Human Papillary Thyroid Carcinoma. IRANIAN JOURNAL OF PATHOLOGY 2019; 14:290-298. [PMID: 31754358 PMCID: PMC6824767 DOI: 10.30699/ijp.2019.94401.1922] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 07/27/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND & OBJECTIVE Papillary thyroid cancer (PTC) is considered to be the most common type of thyroid malignancies. Epigenetic alteration, in which the chromatin conformation and gene expression change without changing the sequence of DNA, can occur in some tumor suppressor genes and oncogenes. Methylation is the most common type of epigenetic alterations that can be an excellent indicator of PTC invasive behavior. METHODS In this research, we determined the promoter methylation status of four tumor suppressor genes (SLC5A8, RASSF1, MGMT, and DNMT1) and compared the results of 55 PTC cases with 40 goiter patients. For methylation, we used the methylation-sensitive high resolution melting (MS-HRM) assay technique. The resulting graphs of each run were compared with those of 0%, 50%, and 100% methylated controls. RESULTS Our data showed that the promoter methylation of SLC5A8, Ras association domain family member 1(RASSF1), and MGMT were significantly different between PTC tissue and goiter with P-value less than 0.05. The most significant differences were observed in RASSF1; 77.2% of hyper-methylated PTC patients versus 15.6% hyper-methylated goiter samples (P<0.001). CONCLUSION RASSF1 promoter methylation can be a PTC genetic marker. RASSF1 promoter methylation is under the impact of the methyltransferase genes (DNMT1 and MGMT), protein expression, and promoter methylation.
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Affiliation(s)
- Fatemeh Khatami
- Chronic Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Bagher Larijani
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Ramin Heshmat
- Chronic Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Shirzad Nasiri
- Department of Surgery, Tehran University of Medical Sciences, Shariati Hospital, Tehran, Iran
| | - Hiva Saffar
- Department of Pathology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Gita Shafiee
- Chronic Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Azam Mossafa
- Department of Surgery, Tehran University of Medical Sciences, Shariati Hospital, Tehran, Iran
| | - Seyed Mohammad Tavangar
- Chronic Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pathology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
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11
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Tsai MH, Pai LM, Lee CK. Fine-Tuning of Type I Interferon Response by STAT3. Front Immunol 2019; 10:1448. [PMID: 31293595 PMCID: PMC6606715 DOI: 10.3389/fimmu.2019.01448] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 06/10/2019] [Indexed: 12/20/2022] Open
Abstract
Type I interferon (IFN-I) is induced during innate immune response and is required for initiating antiviral activity, growth inhibition, and immunomodulation. STAT1, STAT2, and STAT3 are activated in response to IFN-I stimulation. STAT1, STAT2, and IRF9 form ISGF3 complex which transactivates downstream IFN-stimulated genes and mediates antiviral response. However, the role of STAT3 remains to be characterized. Here, we review the multiple actions of STAT3 on suppressing IFN-I responses, including blocking IFN-I signaling, downregulating the expression of ISGF3 components, and antagonizing the transcriptional activity of ISGF3. Finally, we discuss the evolution of the suppressive activity of STAT3 and the therapeutic potential of STAT3 inhibitors in host defense against viral infections and IFN-I-associated diseases.
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Affiliation(s)
- Ming-Hsun Tsai
- Graduate Institute of Immunology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Li-Mei Pai
- Department of Biochemistry and Molecular Biology, Chang Gung University, Taoyuan, Taiwan.,Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan.,Liver Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Chien-Kuo Lee
- Graduate Institute of Immunology, National Taiwan University College of Medicine, Taipei, Taiwan
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12
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Transcriptional and epigenetic regulation of immune tolerance: roles of the NF-κB family members. Cell Mol Immunol 2019; 16:315-323. [PMID: 30872809 DOI: 10.1038/s41423-019-0202-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 01/15/2019] [Indexed: 01/06/2023] Open
Abstract
Immune tolerance is a highly regulated state and involves diverse mechanisms. Central to the induction of tolerance is the targeted modulation of T-cell activities (both effector and regulatory), in which transcription factors play a significant role. The nuclear factor kappa-B (NF-κB) family is a family of transcription factors that not only are critically involved in diverse T-cell responses but also are regulated by many mechanisms to maintain tolerance and T-cell homeostasis. NF-κB, as a transcription factor, has been extensively studied in recent decades, and the molecular mechanisms that regulate NF-κB activities have been well documented. However, recent studies have revealed exciting new roles for NF-κB; in addition to its transcriptional activity, NF-κB can also activate diverse epigenetic mechanisms that mediate extensive chromatin remodeling of target genes to regulate T-cell activities. In this review article, we highlight recent discoveries and emerging opportunities in targeting NF-κB family members as well as their associated chromatin modifiers in the induction of immune tolerance and in the clinical treatment of immune diseases.
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13
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Molecular Mechanisms Related to Hormone Inhibition Resistance in Prostate Cancer. Cells 2019; 8:cells8010043. [PMID: 30642011 PMCID: PMC6356740 DOI: 10.3390/cells8010043] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/04/2019] [Accepted: 01/08/2019] [Indexed: 12/19/2022] Open
Abstract
Management of metastatic or advanced prostate cancer has acquired several therapeutic approaches that have drastically changed the course of the disease. In particular due to the high sensitivity of prostate cancer cells to hormone depletion, several agents able to inhibit hormone production or binding to nuclear receptor have been evaluated and adopted in clinical practice. However, despite several hormonal treatments being available nowadays for the management of advanced or metastatic prostate cancer, the natural history of the disease leads inexorably to the development of resistance to hormone inhibition. Findings regarding the mechanisms that drive this process are of particular and increasing interest as these are potentially related to the identification of new targetable pathways and to the development of new drugs able to improve our patients' clinical outcomes.
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14
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BIRC3 Expression Predicts CLL Progression and Defines Treatment Sensitivity via Enhanced NF-κB Nuclear Translocation. Clin Cancer Res 2018; 25:1901-1912. [DOI: 10.1158/1078-0432.ccr-18-1548] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 09/24/2018] [Accepted: 11/20/2018] [Indexed: 11/16/2022]
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15
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Stone OA, El-Brolosy M, Wilhelm K, Liu X, Romão AM, Grillo E, Lai JKH, Günther S, Jeratsch S, Kuenne C, Lee IC, Braun T, Santoro MM, Locasale JW, Potente M, Stainier DYR. Loss of pyruvate kinase M2 limits growth and triggers innate immune signaling in endothelial cells. Nat Commun 2018; 9:4077. [PMID: 30301887 PMCID: PMC6177464 DOI: 10.1038/s41467-018-06406-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 09/01/2018] [Indexed: 12/11/2022] Open
Abstract
Despite their inherent proximity to circulating oxygen and nutrients, endothelial cells (ECs) oxidize only a minor fraction of glucose in mitochondria, a metabolic specialization that is poorly understood. Here we show that the glycolytic enzyme pyruvate kinase M2 (PKM2) limits glucose oxidation, and maintains the growth and epigenetic state of ECs. We find that loss of PKM2 alters mitochondrial substrate utilization and impairs EC proliferation and migration in vivo. Mechanistically, we show that the NF-κB transcription factor RELB is responsive to PKM2 loss, limiting EC growth through the regulation of P53. Furthermore, S-adenosylmethionine synthesis is impaired in the absence of PKM2, resulting in DNA hypomethylation, de-repression of endogenous retroviral elements (ERVs) and activation of antiviral innate immune signalling. This work reveals the metabolic and functional consequences of glucose oxidation in the endothelium, highlights the importance of PKM2 for endothelial growth and links metabolic dysfunction with autoimmune activation in ECs.
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Affiliation(s)
- Oliver A Stone
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231, Bad Nauheim, Germany.
- Department of Physiology, Anatomy and Genetics, BHF Centre of Research Excellence, University of Oxford, Oxford, OX1 3PT, UK.
| | - Mohamed El-Brolosy
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231, Bad Nauheim, Germany
| | - Kerstin Wilhelm
- Angiogenesis & Metabolism Laboratory, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231, Bad Nauheim, Germany
| | - Xiaojing Liu
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Ana M Romão
- Department of Cardiac Development and Remodelling, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231, Bad Nauheim, Germany
| | | | - Jason K H Lai
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231, Bad Nauheim, Germany
- Mechanobiology Institute, National University of Singapore, Singapore, 117411, Singapore
| | - Stefan Günther
- ECCPS Bioinformatics and Deep Sequencing Platform, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231, Bad Nauheim, Germany
| | - Sylvia Jeratsch
- Biomolecular Mass Spectrometry, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231, Bad Nauheim, Germany
| | - Carsten Kuenne
- ECCPS Bioinformatics and Deep Sequencing Platform, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231, Bad Nauheim, Germany
| | - I-Ching Lee
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231, Bad Nauheim, Germany
| | - Thomas Braun
- Department of Cardiac Development and Remodelling, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231, Bad Nauheim, Germany
| | - Massimo M Santoro
- Department of Biology, University of Padua, Viale Giuseppe Colombo 3, 10141, Padua, Italy
| | - Jason W Locasale
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Michael Potente
- Angiogenesis & Metabolism Laboratory, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231, Bad Nauheim, Germany
| | - Didier Y R Stainier
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231, Bad Nauheim, Germany
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16
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Struzik J, Szulc-Dąbrowska L. Manipulation of Non-canonical NF-κB Signaling by Non-oncogenic Viruses. Arch Immunol Ther Exp (Warsz) 2018; 67:41-48. [PMID: 30196473 PMCID: PMC6433803 DOI: 10.1007/s00005-018-0522-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 06/19/2018] [Indexed: 02/07/2023]
Abstract
Nuclear factor (NF)-κB is a major regulator of antiviral response. Viral pathogens exploit NF-κB activation pathways to avoid cellular mechanisms that eliminate the infection. Canonical (classical) NF-κB signaling, which regulates innate immune response, cell survival and inflammation, is often manipulated by viral pathogens that can counteract antiviral response. Oncogenic viruses can modulate not only canonical, but also non-canonical (alternative) NF-κB activation pathways. The non-canonical NF-κB signaling is responsible for adaptive immunity and plays a role in lymphoid organogenesis, B cell development, as well as bone metabolism. Thus, non-canonical NF-κB activation has been linked to lymphoid malignancies. However, some data strongly suggest that the non-canonical NF-κB activation pathway may also function in innate immunity and is modulated by certain non-oncogenic viruses. Collectively, these findings show the importance of studying the impact of different groups of viral pathogens on alternative NF-κB activation. This mini-review focuses on the influence of non-oncogenic viruses on the components of non-canonical NF-κB signaling.
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Affiliation(s)
- Justyna Struzik
- Division of Immunology, Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences-SGGW, Ciszewskiego 8, 02-786, Warsaw, Poland.
| | - Lidia Szulc-Dąbrowska
- Division of Immunology, Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences-SGGW, Ciszewskiego 8, 02-786, Warsaw, Poland
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17
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Amair-Pinedo F, Matos I, Saurí T, Hernando J, Capdevila J. The Treatment Landscape and New Opportunities of Molecular Targeted Therapies in Gastroenteropancreatic Neuroendocrine Tumors. Target Oncol 2018; 12:757-774. [PMID: 29143176 DOI: 10.1007/s11523-017-0532-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Neuroendocrine neoplasms (NENs) are a heterogeneous group of neoplasms that originate from neuroendocrine stem cells and express both neural and endocrine markers. They are found in almost every organ, and while NENs are mostly associated with slow growth, complications due to the uncontrolled secretion of active peptides, and metastatic disease, may significantly impair the quality of life and can ultimately lead to the death of affected individuals. Expanding knowledge of the genetic, epigenetic, and proteomic landscapes of NENs has led to a better understanding of their molecular pathology and consequently increased treatment options for patients. Here, we review the principal breakthroughs in NEN treatment management, owing largely to omics technologies over the last few years, current recommendations of systemic treatment, and ongoing research into the identification of predictive and response biomarkers based on molecular targeted therapies.
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Affiliation(s)
| | - Ignacio Matos
- Vall d'Hebron University Hospital, Barcelona, Spain.,Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - Tamara Saurí
- Vall d'Hebron University Hospital, Barcelona, Spain.,Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - Jorge Hernando
- Vall d'Hebron University Hospital, Barcelona, Spain.,Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - Jaume Capdevila
- Vall d'Hebron University Hospital, Barcelona, Spain. .,Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain.
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18
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Boosani CS, Gunasekar P, Block M, Jiang W, Zhang Z, Radwan MM, Agrawal DK. Inhibition of DNA methyltransferase-1 instigates the expression of DNA methyltransferase-3a in angioplasty-induced restenosis. Can J Physiol Pharmacol 2018; 96:1030-1039. [PMID: 30067080 DOI: 10.1139/cjpp-2018-0111] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Increased expression of DNA methyltransferase-1 (DNMT1) associates with the progression of many human diseases. Because DNMT1 induces cell proliferation, drugs that inhibit DNMT1 have been used to treat proliferative diseases. Because these drugs are nonspecific inhibitors of DNMT1, subsidiary events or the compensatory mechanisms that are activated in the absence of DNMT1 limit their therapeutic application. Here, we studied the molecular mechanisms that occur during angioplasty-induced restenosis and found that DNMT1 inhibition in both in vitro and in vivo approaches resulted in the induction of DNA methyltransferase-3a (DNMT3a) expression. In vascular smooth muscle cells (VSMCs), the microRNA hsa-miR-1264 mimic, specifically inhibiting DNMT1, induced nuclear expression of DNMT3a. On the contrary, there was no induced expression of DNMT3a in VSMCs that were transfected with hsa-miR-1264 inhibitor. Further, ectopic expression of suppressor of cytokine signaling 3 (SOCS3) through adeno-associated virus (AAV)-mediated gene delivery in the coronary arteries of Yucatan microswine showed inhibition of both DNMT1 and DNMT3a in vivo. These findings show the existence of an inter-regulatory mechanism between DNMT1 and DNMT3a where, in the absence of DNMT1, induction of DNMT3a compensates for the loss of DNMT1 functions, suggesting that the inhibition of both DNMT1 and DNMT3a are required to prevent restenosis.
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Affiliation(s)
- Chandra S Boosani
- Department of Clinical & Translational Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA.,Department of Clinical & Translational Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA
| | - Palanikumar Gunasekar
- Department of Clinical & Translational Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA.,Department of Clinical & Translational Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA
| | - Megan Block
- Department of Clinical & Translational Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA.,Department of Clinical & Translational Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA
| | - Wanlin Jiang
- Department of Clinical & Translational Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA.,Department of Clinical & Translational Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA
| | - Zefu Zhang
- Department of Clinical & Translational Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA.,Department of Clinical & Translational Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA
| | - Mohamed M Radwan
- Department of Clinical & Translational Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA.,Department of Clinical & Translational Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA
| | - Devendra K Agrawal
- Department of Clinical & Translational Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA
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19
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STAT3 Interactors as Potential Therapeutic Targets for Cancer Treatment. Int J Mol Sci 2018; 19:ijms19061787. [PMID: 29914167 PMCID: PMC6032216 DOI: 10.3390/ijms19061787] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 06/13/2018] [Accepted: 06/14/2018] [Indexed: 02/07/2023] Open
Abstract
Signal transducers and activators of transcription (STATs) mediate essential signaling pathways in different biological processes, including immune responses, hematopoiesis, and neurogenesis. Among the STAT members, STAT3 plays crucial roles in cell proliferation, survival, and differentiation. While STAT3 activation is transient in physiological conditions, STAT3 becomes persistently activated in a high percentage of solid and hematopoietic malignancies (e.g., melanoma, multiple myeloma, breast, prostate, ovarian, and colon cancers), thus contributing to malignant transformation and progression. This makes STAT3 an attractive therapeutic target for cancers. Initial strategies aimed at inhibiting STAT3 functions have focused on blocking the action of its activating kinases or sequestering its DNA binding ability. More recently, the diffusion of proteomic-based techniques, which have allowed for the identification and characterization of novel STAT3-interacting proteins able to modulate STAT3 activity via its subcellular localization, interact with upstream kinases, and recruit transcriptional machinery, has raised the possibility to target such cofactors to specifically restrain STAT3 oncogenic functions. In this article, we summarize the available data about the function of STAT3 interactors in malignant cells and discuss their role as potential therapeutic targets for cancer treatment.
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20
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Noncanonical NF-κB in Cancer. Biomedicines 2018; 6:biomedicines6020066. [PMID: 29874793 PMCID: PMC6027307 DOI: 10.3390/biomedicines6020066] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 05/31/2018] [Accepted: 06/04/2018] [Indexed: 12/31/2022] Open
Abstract
The NF-κB pathway is a critical regulator of immune responses and is often dysregulated in cancer. Two NF-κB pathways have been described to mediate these responses, the canonical and the noncanonical. While understudied compared to the canonical NF-κB pathway, noncanonical NF-κB and its components have been shown to have effects, usually protumorigenic, in many different cancer types. Here, we review noncanonical NF-κB pathways and discuss its important roles in promoting cancer. We also discuss alternative NF-κB-independent functions of some the components of noncanonical NF-κB signaling. Finally, we discuss important crosstalk between canonical and noncanonical signaling, which blurs the two pathways, indicating that understanding the full picture of NF-κB regulation is critical to deciphering how this broad pathway promotes oncogenesis.
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21
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Ko TY, Kim JI, Park ES, Mun JM, Park SD. The Clinical Implications of Death Domain-Associated Protein (DAXX) Expression. THE KOREAN JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY 2018; 51:187-194. [PMID: 29854663 PMCID: PMC5973215 DOI: 10.5090/kjtcs.2018.51.3.187] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/01/2017] [Accepted: 11/01/2017] [Indexed: 01/10/2023]
Abstract
Background Death domain-associated protein (DAXX), originally identified as a pro-apoptotic protein, is now understood to be either a pro-apoptotic or an anti-apoptotic factor with a chromatin remodeler, depending on the cell type and context. This study evaluated DAXX expression and its clinical implications in squamous cell carcinoma of the esophagus. Methods Paraffin-embedded tissues from 60 cases of esophageal squamous carcinoma were analyzed immunohistochemically. An immune reaction with more than 10% of tumor cells was interpreted as positive. Positive reactions were sorted into 2 groups: reactions in 11%–50% of tumor cells and reactions in more than 51% of tumor cells, and the correlations between expression and survival and clinical prognosticators were analyzed. Results Forty-three of the 60 cases (71.7%) showed strong nuclear DAXX expression, among which 19 cases showed a positive reaction (31.7%) in 11%–50% of tumor cells, and 24 cases (40.0%) showed a positive reaction in more than 51% of tumor cells. A negative reaction was found in 17 cases (28.3%). These patterns of immunostaining were significantly associated with the N stage (p=0.005) and American Joint Committee on Cancer stage (p=0.001), but overall survival showed no significant difference. There were no correlations of DAXX expression with age, gender, or T stage. However, in stage IIB (p=0.046) and stage IV (p=0.014) disease, DAXX expression was significantly correlated with survival. Conclusion This investigation found upregulation of DAXX in esophageal cancer, with a 71.7% expression rate. DAXX immunostaining could be used in clinical practice to predict aggressive tumors with lymph node metastasis in advanced-stage disease, especially in stages IIB and IV.
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Affiliation(s)
- Taek Yong Ko
- Department of Thoracic and Cardiovascular Surgery, Kosin University Gospel Hospital, Kosin University College of Medicine
| | - Jong In Kim
- Department of Thoracic and Cardiovascular Surgery, Kosin University Gospel Hospital, Kosin University College of Medicine
| | - Eok Sung Park
- Department of Thoracic and Cardiovascular Surgery, Haeundae Bumin Hospital
| | - Jeong Min Mun
- Department of Thoracic and Cardiovascular Surgery, Kosin University Gospel Hospital, Kosin University College of Medicine
| | - Sung Dal Park
- Department of Thoracic and Cardiovascular Surgery, Kosin University Gospel Hospital, Kosin University College of Medicine
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22
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Asuri S, McIntosh S, Taylor V, Rokeby A, Kelly J, Shumansky K, Field LL, Yoshida EM, Arbour L. Primary Biliary Cholangitis in British Columbia First Nations: Clinical features and discovery of novel genetic susceptibility loci. Liver Int 2018; 38:940-948. [PMID: 29297981 DOI: 10.1111/liv.13686] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 12/21/2017] [Indexed: 02/13/2023]
Abstract
BACKGROUND & AIMS Primary Biliary Cholangitis (PBC) is a chronic autoimmune liver disease characterized by destruction of intrahepatic bile ducts, portal inflammation and cirrhosis. Although rare in most populations, it is prevalent and often familial in British Columbia First Nations. We hypothesized that major genetic factors increased the risk in First Nations. METHODS In all, 44 individuals with Primary Biliary Cholangitis and 61 unaffected relatives from 32 First Nations families participated. Family history and co-morbidities were documented. Medical records were reviewed and available biopsies were re-reviewed by our team pathologist. Genotyping was performed on DNA from 36 affected persons and 27 unaffected relatives using the Affymetrix Human Mapping 500K Array Set. MERLIN software was used to carry out multipoint parametric and nonparametric linkage analysis. Candidate genes were identified and entered into InnateDB and KEGG software to identify potential pathways affecting pathogenesis. RESULTS In all, 34% of families were multiplex. Fifty per cent of cases and 33% of unaffected relatives reported other autoimmune disease. Three genomic regions (9q21, 17p13 and 19p13) produced LOD scores of 2.3 or greater suggestive of linkage, but no single linkage peak reached statistical significance. Candidate genes identified in the three regions suggested involvement of IL17, NFκB, IL6, JAK-STAT, IFNγ and TGFβ immune signalling pathways. Specifically, four genes-ACT1, PIN1, DNMT1 and NTN1-emerged as having roles in these pathways that may influence Primary Biliary Cholangitis pathogenesis. CONCLUSIONS Our whole genome linkage study results reflect the multifactorial nature of Primary Biliary Cholangitis, support previous studies suggesting signalling pathway involvement and identify new candidate genes for consideration.
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Affiliation(s)
- Sirisha Asuri
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Sarah McIntosh
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Valerie Taylor
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Andrew Rokeby
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - James Kelly
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Karey Shumansky
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Lanora Leigh Field
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Eric M Yoshida
- Division of Gastroenterology, University of British Columbia, Vancouver, BC, Canada
| | - Laura Arbour
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
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23
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Hervouet E, Peixoto P, Delage-Mourroux R, Boyer-Guittaut M, Cartron PF. Specific or not specific recruitment of DNMTs for DNA methylation, an epigenetic dilemma. Clin Epigenetics 2018; 10:17. [PMID: 29449903 PMCID: PMC5807744 DOI: 10.1186/s13148-018-0450-y] [Citation(s) in RCA: 144] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 01/30/2018] [Indexed: 11/28/2022] Open
Abstract
Our current view of DNA methylation processes is strongly moving: First, even if it was generally admitted that DNMT3A and DNMT3B are associated with de novo methylation and DNMT1 is associated with inheritance DNA methylation, these distinctions are now not so clear. Secondly, since one decade, many partners of DNMTs have been involved in both the regulation of DNA methylation activity and DNMT recruitment on DNA. The high diversity of interactions and the combination of these interactions let us to subclass the different DNMT-including complexes. For example, the DNMT3L/DNMT3A complex is mainly related to de novo DNA methylation in embryonic states, whereas the DNMT1/PCNA/UHRF1 complex is required for maintaining global DNA methylation following DNA replication. On the opposite to these unspecific DNA methylation machineries (no preferential DNA sequence), some recently identified DNMT-including complexes are recruited on specific DNA sequences. The coexistence of both types of DNA methylation (un/specific) suggests a close cooperation and an orchestration between these systems to maintain genome and epigenome integrities. Deregulation of these systems can lead to pathologic disorders.
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Affiliation(s)
- Eric Hervouet
- INSERM unit 1098, University of Bourgogne Franche-Comté, Besançon, France.,EPIGENExp (EPIgenetics and GENe EXPression Technical Platform), Besançon, France
| | - Paul Peixoto
- INSERM unit 1098, University of Bourgogne Franche-Comté, Besançon, France.,EPIGENExp (EPIgenetics and GENe EXPression Technical Platform), Besançon, France
| | | | | | - Pierre-François Cartron
- 3INSERM unit S1232, University of Nantes, Nantes, France.,4Institut de cancérologie de l'Ouest, Nantes, France.,REpiCGO (Cancéropole Grand-Ouest), Nantes, France.,EpiSAVMEN Networks, Nantes, Région Pays de la Loire France
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24
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Autophagy acts through TRAF3 and RELB to regulate gene expression via antagonism of SMAD proteins. Nat Commun 2017; 8:1537. [PMID: 29146913 PMCID: PMC5691083 DOI: 10.1038/s41467-017-00859-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 08/01/2017] [Indexed: 01/17/2023] Open
Abstract
Macroautophagy can regulate cell signalling and tumorigenesis via elusive molecular mechanisms. We establish a RAS mutant cancer cell model where the autophagy gene ATG5 is dispensable in A549 cells in vitro, yet promotes tumorigenesis in mice. ATG5 represses transcriptional activation by the TGFβ-SMAD gene regulatory pathway. However, autophagy does not terminate cytosolic signal transduction by TGFβ. Instead, we use proteomics to identify selective degradation of the signalling scaffold TRAF3. TRAF3 autophagy is driven by RAS and results in activation of the NF-κB family member RELB. We show that RELB represses TGFβ target promoters independently of DNA binding at NF-κB recognition sequences, instead binding with SMAD family member(s) at SMAD-response elements. Thus, autophagy antagonises TGFβ gene expression. Finally, autophagy-deficient A549 cells regain tumorigenicity upon SMAD4 knockdown. Thus, at least in this setting, a physiologic function for autophagic regulation of gene expression is tumour growth. Macroautophagy can regulate cell signalling and tumorigenesis but the molecular mechanisms are unclear. Here the authors show selective degradation of the signalling scaffold TRAF3 by autophagy and consequent activation of the NF-κB family member RELB regulate gene expression via antagonism of SMAD proteins.
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25
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Hoelper D, Huang H, Jain AY, Patel DJ, Lewis PW. Structural and mechanistic insights into ATRX-dependent and -independent functions of the histone chaperone DAXX. Nat Commun 2017; 8:1193. [PMID: 29084956 PMCID: PMC5662737 DOI: 10.1038/s41467-017-01206-y] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 08/29/2017] [Indexed: 12/20/2022] Open
Abstract
The ATRX-DAXX histone chaperone complex incorporates the histone variant H3.3 at heterochromatic regions in a replication-independent manner. Here, we present a high-resolution x-ray crystal structure of an interaction surface between ATRX and DAXX. We use single amino acid substitutions in DAXX that abrogate formation of the complex to explore ATRX-dependent and ATRX-independent functions of DAXX. We find that the repression of specific murine endogenous retroviruses is dependent on DAXX, but not on ATRX. In support, we reveal the existence of two biochemically distinct DAXX-containing complexes: the ATRX-DAXX complex involved in gene repression and telomere chromatin structure, and a DAXX-SETDB1-KAP1-HDAC1 complex that represses endogenous retroviruses independently of ATRX and H3.3 incorporation into chromatin. We find that histone H3.3 stabilizes DAXX protein levels and can affect DAXX-regulated gene expression without incorporation into nucleosomes. Our study demonstrates a nucleosome-independent function for the H3.3 histone variant.
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Affiliation(s)
- Dominik Hoelper
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI, 53706, USA
- Wisconsin Institute for Discovery, University of Wisconsin, Madison, WI, 53715, USA
| | - Hongda Huang
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
- Department of Biology, South University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Aayushi Y Jain
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI, 53706, USA
- Wisconsin Institute for Discovery, University of Wisconsin, Madison, WI, 53715, USA
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Peter W Lewis
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI, 53706, USA.
- Wisconsin Institute for Discovery, University of Wisconsin, Madison, WI, 53715, USA.
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26
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Di Domenico A, Wiedmer T, Marinoni I, Perren A. Genetic and epigenetic drivers of neuroendocrine tumours (NET). Endocr Relat Cancer 2017; 24:R315-R334. [PMID: 28710117 DOI: 10.1530/erc-17-0012] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 07/14/2017] [Indexed: 12/13/2022]
Abstract
Neuroendocrine tumours (NET) of the gastrointestinal tract and the lung are a rare and heterogeneous group of tumours. The molecular characterization and the clinical classification of these tumours have been evolving slowly and show differences according to organs of origin. Novel technologies such as next-generation sequencing revealed new molecular aspects of NET over the last years. Notably, whole-exome/genome sequencing (WES/WGS) approaches underlined the very low mutation rate of well-differentiated NET of all organs compared to other malignancies, while the engagement of epigenetic changes in driving NET evolution is emerging. Indeed, mutations in genes encoding for proteins directly involved in chromatin remodelling, such as DAXX and ATRX are a frequent event in NET. Epigenetic changes are reversible and targetable; therefore, an attractive target for treatment. The discovery of the mechanisms underlying the epigenetic changes and the implication on gene and miRNA expression in the different subgroups of NET may represent a crucial change in the diagnosis of this disease, reveal new therapy targets and identify predictive markers. Molecular profiles derived from omics data including DNA mutation, methylation, gene and miRNA expression have already shown promising results in distinguishing clinically and molecularly different subtypes of NET. In this review, we recapitulate the major genetic and epigenetic characteristics of pancreatic, lung and small intestinal NET and the affected pathways. We also discuss potential epigenetic mechanisms leading to NET development.
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Affiliation(s)
- Annunziata Di Domenico
- Institute of PathologyUniversity of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical SciencesUniversity of Bern, Bern, Switzerland
| | - Tabea Wiedmer
- Institute of PathologyUniversity of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical SciencesUniversity of Bern, Bern, Switzerland
| | | | - Aurel Perren
- Institute of PathologyUniversity of Bern, Bern, Switzerland
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27
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PTEN regulates glioblastoma oncogenesis through chromatin-associated complexes of DAXX and histone H3.3. Nat Commun 2017; 8:15223. [PMID: 28497778 PMCID: PMC5437297 DOI: 10.1038/ncomms15223] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 03/10/2017] [Indexed: 01/05/2023] Open
Abstract
Glioblastoma (GBM) is the most lethal type of human brain cancer, where deletions and mutations in the tumour suppressor gene PTEN (phosphatase and tensin homolog) are frequent events and are associated with therapeutic resistance. Herein, we report a novel chromatin-associated function of PTEN in complex with the histone chaperone DAXX and the histone variant H3.3. We show that PTEN interacts with DAXX and, in turn PTEN directly regulates oncogene expression by modulating DAXX-H3.3 association on the chromatin, independently of PTEN enzymatic activity. Furthermore, DAXX inhibition specifically suppresses tumour growth and improves the survival of orthotopically engrafted mice implanted with human PTEN-deficient glioma samples, associated with global H3.3 genomic distribution changes leading to upregulation of tumour suppressor genes and downregulation of oncogenes. Moreover, DAXX expression anti-correlates with PTEN expression in GBM patient samples. Since loss of chromosome 10 and PTEN are common events in cancer, this synthetic growth defect mediated by DAXX suppression represents a therapeutic opportunity to inhibit tumorigenesis specifically in the context of PTEN deletion. PTEN mutations are frequent in glioblastoma and often are associated with therapeutic resistance. Here, the authors demonstrate that PTEN regulates gene expression at the chromatin level by interacting with the histone chaperone DAXX and H3.3, and that DAXX inhibition inhibits PTEN-deficient GBM growth in vivo.
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28
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Marinoni I, Wiederkeher A, Wiedmer T, Pantasis S, Di Domenico A, Frank R, Vassella E, Schmitt A, Perren A. Hypo-methylation mediates chromosomal instability in pancreatic NET. Endocr Relat Cancer 2017; 24:137-146. [PMID: 28115389 DOI: 10.1530/erc-16-0554] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 01/23/2017] [Indexed: 12/22/2022]
Abstract
DAXX and or ATRX loss occur in 40% of pancreatic neuroendocrine tumors (PanNETs). PanNETs negative for DAXX or ATRX show an increased risk of relapse. The tumor-associated pathways activated upon DAXX or ATRX loss and how this event may induce chromosomal instability (CIN) and alternative lengthening telomeres (ALT) are still unknown. Both DAXX and ATRX are involved in DNA methylation regulation. DNA methylation of heterochromatin and of non-coding sequences is extremely important for the maintenance of genomic stability. We analyzed the association of DAXX and/or ATRX loss and CIN with global DNA methylation in human PanNET samples and the effect of DAXX knock-down on methylation and cell proliferation. We assessed LINE1 as well as global DNA methylation in 167 PanNETs, and we found that DAXX and or ATRX-negative tumors and tumors with CIN were hypomethylated. DAXX knock-down in PanNET cell lines blocked cells in G1/G0 phase and seemed to increase CIN in QGP-1 cells. However, no direct changes in DNA methylation were observed after DAXX knock-down in vitro In conclusion, our data indicate that epigenetic changes are crucial steps in the progression of PanNETs loss and suggest that DNA methylation is the mechanism via which CIN is induced, allowing clonal expansion and selection.
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Affiliation(s)
- I Marinoni
- Institute of PathologyUniversity of Bern, Bern, Switzerland
| | - A Wiederkeher
- Institute of PathologyUniversity of Bern, Bern, Switzerland
| | - T Wiedmer
- Institute of PathologyUniversity of Bern, Bern, Switzerland
- GCB Graduate School BernBern, Switzerland
| | - S Pantasis
- Institute of PathologyUniversity of Bern, Bern, Switzerland
| | - A Di Domenico
- Institute of PathologyUniversity of Bern, Bern, Switzerland
- GCB Graduate School BernBern, Switzerland
| | - R Frank
- Institute of PathologyUniversity of Bern, Bern, Switzerland
| | - E Vassella
- Institute of PathologyUniversity of Bern, Bern, Switzerland
| | - A Schmitt
- Institute of PathologyUniversity of Bern, Bern, Switzerland
| | - A Perren
- Institute of PathologyUniversity of Bern, Bern, Switzerland
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29
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Lin CW, Wang LK, Wang SP, Chang YL, Wu YY, Chen HY, Hsiao TH, Lai WY, Lu HH, Chang YH, Yang SC, Lin MW, Chen CY, Hong TM, Yang PC. Daxx inhibits hypoxia-induced lung cancer cell metastasis by suppressing the HIF-1α/HDAC1/Slug axis. Nat Commun 2016; 7:13867. [PMID: 28004751 PMCID: PMC5192219 DOI: 10.1038/ncomms13867] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 11/07/2016] [Indexed: 12/20/2022] Open
Abstract
Hypoxia is a major driving force of cancer invasion and metastasis. Here we show that death domain-associated protein (Daxx) acts to negatively regulate hypoxia-induced cell dissemination and invasion by inhibiting the HIF-1α/HDAC1/Slug pathway. Daxx directly binds to the DNA-binding domain of Slug, impeding histone deacetylase 1 (HDAC1) recruitment and antagonizing Slug E-box binding. This, in turn, stimulates E-cadherin and occludin expression and suppresses Slug-mediated epithelial–mesenchymal transition (EMT) and cell invasiveness. Under hypoxic conditions, stabilized hypoxia-inducible factor (HIF)-1α downregulates Daxx expression and promotes cancer invasion, whereas re-expression of Daxx represses hypoxia-induced cancer invasion. Daxx also suppresses Slug-mediated lung cancer metastasis in an orthotopic lung metastasis mouse model. Using clinical tumour samples, we confirmed that the HIF-1α/Daxx/Slug pathway is an outcome predictor. Our results support that Daxx can act as a repressor in controlling HIF-1α/HDAC1/Slug-mediated cancer cell invasion and is a potential therapeutic target for inhibition of cancer metastasis. Hypoxia and epithelial-to-mesenchymal transition promotes cancer metastasis. Here the authors show that Daxx inhibits hypoxia-induced lung cancer metastasis by attenuating Slug-mediated transcriptional repression of epithelial-like markers that in turn cause cells to exhibit low invasiveness.
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Affiliation(s)
- Ching-Wen Lin
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Lu-Kai Wang
- Radiation Biology Core Laboratory of Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan
| | - Shu-Ping Wang
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York 10065, USA
| | - Yi-Liang Chang
- Department of Pathology and Graduate Institute of Pathology, National Taiwan University College of Medicine, Taipei 10051, Taiwan
| | - Yi-Ying Wu
- Graduate Institute of Clinical Medicine, National Cheng Kung University, Tainan 70101, Taiwan
| | - Hsuan-Yu Chen
- Institute of Statistical Science, Academia Sinica, Taipei 11529, Taiwan
| | - Tzu-Hung Hsiao
- Department of Medical Research, Taichung Veterans General Hospital, Taichung 40705, Taiwan
| | - Wei-Yun Lai
- Aptamer Core, Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Hsuan-Hsuan Lu
- Department of Internal Medicine, National Taiwan University College of Medicine, Taipei 10051, Taiwan
| | - Ya-Hsuan Chang
- Institute of Statistical Science, Academia Sinica, Taipei 11529, Taiwan
| | - Shuenn-Chen Yang
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Ming-Wei Lin
- Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei 11221, Taiwan
| | - Chi-Yuan Chen
- Graduate Institute of Health Industry Technology and Research Center for Industry of Human Ecology, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan 33303, Taiwan
| | - Tse-Ming Hong
- Graduate Institute of Clinical Medicine, National Cheng Kung University, Tainan 70101, Taiwan
| | - Pan-Chyr Yang
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan.,Department of Internal Medicine, National Taiwan University College of Medicine, Taipei 10051, Taiwan
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30
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The Role of Nuclear Antiviral Factors against Invading DNA Viruses: The Immediate Fate of Incoming Viral Genomes. Viruses 2016; 8:v8100290. [PMID: 27782081 PMCID: PMC5086622 DOI: 10.3390/v8100290] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 10/10/2016] [Accepted: 10/17/2016] [Indexed: 12/13/2022] Open
Abstract
In recent years, it has been suggested that host cells exert intrinsic mechanisms to control nuclear replicating DNA viruses. This cellular response involves nuclear antiviral factors targeting incoming viral genomes. Herpes simplex virus-1 (HSV-1) is the best-studied model in this context, and it was shown that upon nuclear entry HSV-1 genomes are immediately targeted by components of promyelocytic leukemia nuclear bodies (PML-NBs) and the nuclear DNA sensor IFI16 (interferon gamma inducible protein 16). Based on HSV-1 studies, together with limited examples in other viral systems, these phenomena are widely believed to be a common cellular response to incoming viral genomes, although formal evidence for each virus is lacking. Indeed, recent studies suggest that the case may be different for adenovirus infection. Here we summarize the existing experimental evidence for the roles of nuclear antiviral factors against incoming viral genomes to better understand cellular responses on a virus-by-virus basis. We emphasize that cells seem to respond differently to different incoming viral genomes and discuss possible arguments for and against a unifying cellular mechanism targeting the incoming genomes of different virus families.
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31
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Schmitt AM, Marinoni I, Blank A, Perren A. New Genetics and Genomic Data on Pancreatic Neuroendocrine Tumors: Implications for Diagnosis, Treatment, and Targeted Therapies. Endocr Pathol 2016; 27:200-4. [PMID: 27456058 DOI: 10.1007/s12022-016-9447-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The recent findings on the roles of death-associated protein 6/α-thalassemia/mental retardation X-linked (DAXX/ATRX) in the development of pancreatic neuroendocrine tumors (PanNETs) have led to major advances in the molecular understanding of these rare tumors and open up completely new therapeutic windows. This overview aims at giving a simplified view on these findings and their possible therapeutic implications. The importance of epigenetic changes in PanNET is also underlined by recent findings of a cross-species study on microRNA (miRNA) and messenger RNA (mRNA) profiles in PanNETs.
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Affiliation(s)
- Anja M Schmitt
- Institute of Pathology, University of Bern, Murtenstrasse 31, 3010, Bern, Switzerland.
| | - Ilaria Marinoni
- Institute of Pathology, University of Bern, Murtenstrasse 31, 3010, Bern, Switzerland
| | - Annika Blank
- Institute of Pathology, University of Bern, Murtenstrasse 31, 3010, Bern, Switzerland
| | - Aurel Perren
- Institute of Pathology, University of Bern, Murtenstrasse 31, 3010, Bern, Switzerland
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32
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Baud V, Collares D. Post-Translational Modifications of RelB NF-κB Subunit and Associated Functions. Cells 2016; 5:cells5020022. [PMID: 27153093 PMCID: PMC4931671 DOI: 10.3390/cells5020022] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 04/19/2016] [Accepted: 04/26/2016] [Indexed: 01/02/2023] Open
Abstract
The family of NF-κB transcription factors plays a key role in diverse biological processes, such as inflammatory and immune responses, cell survival and tumor development. Beyond the classical NF-κB activation pathway, a second NF-κB pathway has more recently been uncovered, the so-called alternative NF-κB activation pathway. It has been shown that this pathway mainly controls the activity of RelB, a member of the NF-κB family. Post-translational modifications, such as phosphorylation, acetylation, methylation, ubiquitination and SUMOylation, have recently emerged as a strategy for the fine-tuned regulation of NF-κB. Our review discusses recent progress in the understanding of RelB regulation by post-translational modifications and the associated functions in normal and pathological conditions.
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Affiliation(s)
- Véronique Baud
- NF-κB, Differentiation and Cancer, Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France.
| | - Davi Collares
- NF-κB, Differentiation and Cancer, Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
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33
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Das TP, Suman S, Papu John AMS, Pal D, Edwards A, Alatassi H, Ankem MK, Damodaran C. Activation of AKT negatively regulates the pro-apoptotic function of death-associated protein kinase 3 (DAPK3) in prostate cancer. Cancer Lett 2016; 377:134-9. [PMID: 27126362 PMCID: PMC4884664 DOI: 10.1016/j.canlet.2016.04.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 04/14/2016] [Accepted: 04/17/2016] [Indexed: 01/10/2023]
Abstract
This is the first study that demonstrates the inverse correlation of AKT activation and down-regulation of tumor suppressor protein, DAPK-3, in CaP cell lines as well as human prostate tumor tissues that correlate with disease progression. Either silencing AKT or overexpressing DAPK-3 induces apoptosis in Castration Resistant Prostate Cancer cells.
The activation of AKT governs many signaling pathways and promotes cell growth and inhibits apoptosis in human malignancies including prostate cancer (CaP). Here, we investigated the molecular association between AKT activation and the function of death-associated protein kinase 3 (DAPK3) in CaP. An inverse correlation of pAKT and DAPK3 expression was seen in a panel of CaP cell lines. Inhibition of AKT by wortmannin/LY294002 or overexpression of DAPK3 reverts the proliferative function of AKT in CaP cells. On the other hand, ectopic expression of AKT inhibited DAPK3 function and induced proliferation of CaP cells. In addition, AKT over-expressed tumors exhibit aggressive growth when compared to control vector in xenograft models. The immunohistochemistry results revealed a down-regulation of DAPK3 expression in AKT over-expressed tumors as compared to control tumors. Finally, we examined the expression pattern of AKT and DAPK3 in human CaP specimens – the expected gradual increase and nuclear localization of pAKT was seen in higher Gleason score samples versus benign hyperplasia (BPH). On the contrary, reduced expression of DAPK3 was seen in higher Gleason stages versus BPH. This suggests that inhibition of DAPK3 may be a contributing factor to the carcinogenesis of the prostate. Understanding the mechanism by which AKT negatively regulates DAPK3 function may suggest whether DAPK3 can be a therapeutic target for CaP.
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Affiliation(s)
- Trinath P Das
- Department of Urology, University of Louisville, Louisville, KY, USA
| | - Suman Suman
- Department of Urology, University of Louisville, Louisville, KY, USA
| | | | - Deeksha Pal
- Department of Urology, University of Louisville, Louisville, KY, USA
| | - Angelena Edwards
- Department of Urology, University of Louisville, Louisville, KY, USA
| | - Houda Alatassi
- Department of Pathology, University of Louisville, Louisville, KY, USA
| | - Murali K Ankem
- Department of Urology, University of Louisville, Louisville, KY, USA
| | - Chendil Damodaran
- Department of Urology, University of Louisville, Louisville, KY, USA.
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34
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Svadlenka J, Brazina J, Hanzlikova H, Cermak L, Andera L. Multifunctional adaptor protein Daxx interacts with chromatin-remodelling ATPase Brg1. Biochem Biophys Rep 2015; 5:246-252. [PMID: 28955830 PMCID: PMC5600331 DOI: 10.1016/j.bbrep.2015.12.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 11/25/2015] [Accepted: 12/28/2015] [Indexed: 01/22/2023] Open
Abstract
Multifunctional adapter and chaperone protein Daxx participates in the regulation of a number of mainly transcription-related processes. Most notably in a complex with chromatin-remodelling ATPase ATRX, Daxx serves as a histone H3.3 chaperone at telomeric regions and certain genes. In this report we document that Daxx interacts with another chromatin-remodelling, ATPase Brg1. We confirm the Daxx-Brg1 association both in vitro and in cells and show that Daxx interacts with Brg1 in high-molecular-weight complexes. Ectopic co-expression of Daxx with Brg1 and PML could shift disperse nuclear localisation of Brg1 into PML bodies. Mapping the Daxx-Brg1 interaction revealed that Daxx preferentially binds the region between Brg1 N-terminal QLQ and HSA domains, but also weakly interacts with its C-terminal part. Brg1 interacted with both the central and N-terminal parts of Daxx. SiRNA-mediated down-regulation of Daxx in SW13 adrenal carcinoma cells markedly enhanced expression of Brg1-activated genes CD44 or SCEL, suggesting that Daxx either directly through Brg1 and/or indirectly via other factors is a negative regulator of their transcription. Our findings point to Brg1 as another chromatin-remodelling protein that might similarly, as ATRX, target Daxx to specific chromatin regions where it can carry out its chromatin- and transcription-regulating functions.
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Affiliation(s)
- Jan Svadlenka
- Institute of Molecular Genetics AS CR, Czech Republic
| | - Jan Brazina
- Institute of Molecular Genetics AS CR, Czech Republic
| | | | - Lukas Cermak
- Department of Pathology, New York University School of Medicine, New York, USA
| | - Ladislav Andera
- Institute of Molecular Genetics AS CR, Czech Republic.,Institute of Biotechnology AS CR, Prague, Czech Republic
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35
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Matsuda T, Muromoto R, Sekine Y, Togi S, Kitai Y, Kon S, Oritani K. Signal transducer and activator of transcription 3 regulation by novel binding partners. World J Biol Chem 2015; 6:324-332. [PMID: 26629315 PMCID: PMC4657126 DOI: 10.4331/wjbc.v6.i4.324] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 05/02/2015] [Accepted: 09/02/2015] [Indexed: 02/05/2023] Open
Abstract
Signal transducers and activators of transcription (STATs) mediate essential signals for various biological processes, including immune responses, hematopoiesis, and neurogenesis. STAT3, for example, is involved in the pathogenesis of various human diseases, including cancers, autoimmune and inflammatory disorders. STAT3 activation is therefore tightly regulated at multiple levels to prevent these pathological conditions. A number of proteins have been reported to associate with STAT3 and regulate its activity. These STAT3-interacting proteins function to modulate STAT3-mediated signaling at various steps and mediate the crosstalk of STAT3 with other cellular signaling pathways. This article reviews the roles of novel STAT3 binding partners such as DAXX, zipper-interacting protein kinase, Krüppel-associated box-associated protein 1, Y14, PDZ and LIM domain 2 and signal transducing adaptor protein-2, in the regulation of STAT3-mediated signaling.
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36
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Haney SL, Hlady RA, Opavska J, Klinkebiel D, Pirruccello SJ, Dutta S, Datta K, Simpson MA, Wu L, Opavsky R. Methylation-independent repression of Dnmt3b contributes to oncogenic activity of Dnmt3a in mouse MYC-induced T-cell lymphomagenesis. Oncogene 2015; 34:5436-5446. [PMID: 25639876 PMCID: PMC4533871 DOI: 10.1038/onc.2014.472] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 10/28/2014] [Accepted: 11/25/2014] [Indexed: 12/16/2022]
Abstract
DNA methyltransferase 3A (DNMT3A) catalyzes cytosine methylation of mammalian genomic DNA. In addition to myeloid malignancies, mutations in DNMT3A have been recently reported in T-cell lymphoma and leukemia, implying a possible involvement in the pathogenesis of human diseases. However, the role of Dnmt3a in T-cell transformation in vivo is poorly understood. Here we analyzed the functional consequences of Dnmt3a inactivation in a mouse model of MYC-induced T-cell lymphomagenesis (MTCL). Loss of Dnmt3a delayed tumorigenesis by suppressing cellular proliferation during disease progression. Gene expression profiling and pathway analysis identified upregulation of 17 putative tumor suppressor genes, including DNA methyltransferase Dnmt3b, in Dnmt3a-deficient lymphomas as molecular events potentially responsible for the delayed lymphomagenesis in Dnmt3a(Δ/Δ) mice. Interestingly, promoter and gene body methylation of these genes was not substantially changed between control and Dnmt3a-deficient lymphomas, suggesting that Dnmt3a may inhibit their expression in a methylation-independent manner. Re-expression of both wild type and catalytically inactive Dnmt3a in Dnmt3a(Δ/Δ) lymphoma cells in vitro inhibited Dnmt3b expression, indicating that Dnmt3b upregulation may be directly repressed by Dnmt3a. Importantly, genetic inactivation of Dnmt3b accelerated lymphomagenesis in Dnmt3a(Δ/Δ) mice, demonstrating that upregulation of Dnmt3b is a relevant molecular change in Dnmt3a-deficient lymphomas that inhibits disease progression. Collectively, our data demonstrate an unexpected oncogenic role for Dnmt3a in MTCL through methylation-independent repression of Dnmt3b and possibly other tumor suppressor genes.
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Affiliation(s)
- Staci L. Haney
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Ryan A. Hlady
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Jana Opavska
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - David Klinkebiel
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Samuel J. Pirruccello
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Samikshan Dutta
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Kaustubh Datta
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Melanie A. Simpson
- Department of Biochemistry, University of Nebraska, Lincoln, Nebraska, USA
| | - Lizhao Wu
- Department of Microbiology and Molecular Genetics, Rutgers New Jersey Medical School-Cancer Center, Newark, NJ, USA
| | - Rene Opavsky
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Center for Lymphoma and Leukemia Research, University of Nebraska Medical Center, Omaha, Nebraska, USA
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Kivipõld P, Võsa L, Ustav M, Kurg R. DAXX modulates human papillomavirus early gene expression and genome replication in U2OS cells. Virol J 2015; 12:104. [PMID: 26148509 PMCID: PMC4492069 DOI: 10.1186/s12985-015-0335-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 06/30/2015] [Indexed: 12/02/2022] Open
Abstract
Background The human papillomavirus (HPV) genomes can replicate, and are maintained as autonomously replicating extrachromosomal plasmids in human U2OS cells. Previous studies have shown that HPV genomes are transcriptionally active in U2OS cells and can express the viral early proteins required for initiation and establishment of HPV replication. In the present work, we have examined the involvement of cellular DAXX protein in HPV replication in U2OS cells. Methods We have used indirect immunofluorescence and FISH analysis in order to study HPV replication compartments in U2OS cells. In addition, we have used siRNA knock-down for examining the effect of the DAXX protein on HPV replication and transcription in U2OS cells. Results We show that a portion of HPV replication foci are partially co-localized with components of ND10, cellular DAXX and PML proteins. In addition, we demonstrate that the knock-down of the cellular DAXX protein modulates the HPV genome replication and transcription in U2OS cells – papillomavirus replication is reduced in the absence of this component of ND10. Conclusions The DAXX protein modulates the early gene expression and the transient replication of HPV genomes in U2OS cells.
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Affiliation(s)
- Piia Kivipõld
- Institute of Technology, University of Tartu, Nooruse 1, 50411, Tartu, Estonia.
| | - Liisi Võsa
- Institute of Technology, University of Tartu, Nooruse 1, 50411, Tartu, Estonia.
| | - Mart Ustav
- Institute of Technology, University of Tartu, Nooruse 1, 50411, Tartu, Estonia.
| | - Reet Kurg
- Institute of Technology, University of Tartu, Nooruse 1, 50411, Tartu, Estonia.
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Puto LA, Brognard J, Hunter T. Transcriptional Repressor DAXX Promotes Prostate Cancer Tumorigenicity via Suppression of Autophagy. J Biol Chem 2015; 290:15406-15420. [PMID: 25903140 PMCID: PMC4505457 DOI: 10.1074/jbc.m115.658765] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Indexed: 12/20/2022] Open
Abstract
The DAXX transcriptional repressor was originally associated with apoptotic cell death. However, recent evidence that DAXX represses several tumor suppressor genes, including the DAPK1 and DAPK3 protein kinases, and is up-regulated in many cancers argues that a pro-survival role may predominate in a cancer context. Here, we report that DAXX has potent growth-enhancing effects on primary prostatic malignancy through inhibition of autophagy. Through stable gene knockdown and mouse subcutaneous xenograft studies, we demonstrate that DAXX promotes tumorigenicity of human ALVA-31 and PC3 prostate cancer (PCa) cells in vivo. Importantly, DAXX represses expression of essential autophagy modulators DAPK3 and ULK1 in vivo, revealing autophagy suppression as a mechanism through which DAXX promotes PCa tumorigenicity. Furthermore, DAXX knockdown increases autophagic flux in cultured PCa cells. Finally, interrogation of the Oncomine(TM) database suggests that DAXX overexpression is associated with malignant transformation in several human cancers, including prostate and pancreatic cancers. Thus, DAXX may represent a new cancer biomarker for the detection of aggressive disease, whose tissue-specific down-regulation can serve as an improved therapeutic modality. Our results establish DAXX as a pro-survival protein in PCa and reveal that, in the early stages of tumorigenesis, autophagy suppresses prostate tumor formation.
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Affiliation(s)
- Lorena A Puto
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037
| | - John Brognard
- Cancer Research UK Manchester Institute, University of Manchester, Manchester M20 4BX, United Kingdom
| | - Tony Hunter
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037.
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Puto LA, Benner C, Hunter T. The DAXX co-repressor is directly recruited to active regulatory elements genome-wide to regulate autophagy programs in a model of human prostate cancer. Oncoscience 2015; 2:362-72. [PMID: 26097870 PMCID: PMC4468322 DOI: 10.18632/oncoscience.152] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 04/08/2015] [Indexed: 01/09/2023] Open
Abstract
While carcinoma of the prostate is the second most common cause of cancer death in the US, current methods and markers used to predict prostate cancer (PCa) outcome are inadequate. This study was aimed at understanding the genome-wide binding and regulatory role of the DAXX transcriptional repressor, recently implicated in PCa. ChIP-Seq analysis of genome-wide distribution of DAXX in PC3 cells revealed over 59,000 DAXX binding sites, found at regulatory enhancers and promoters. ChIP-Seq analysis of DNA methyltransferase 1 (DNMT1), which is a key epigenetic partner for DAXX repression, revealed that DNMT1 binding was restricted to a small number of DAXX sites. DNMT1 and DAXX bound close to transcriptional activator motifs. DNMT1 sites were found to be dependent on DAXX for recruitment by analyzing DNMT1 ChIP-Seq following DAXX knockdown (K/D), corroborating previous findings that DAXX recruits DNMT1 to repress its target genes. Massively parallel RNA sequencing (RNA-Seq) was used to compare the transcriptomes of WT and DAXX K/D PC3 cells. Genes induced by DAXX K/D included those involved in autophagy, and DAXX ChIP-Seq peaks were found close to the transcription start sites (TSS) of autophagy genes, implying they are more likely to be regulated by DAXX. In conclusion, DAXX binds active regulatory elements and co-localizes with DNMT1 in the prostate cancer genome. Given DAXX's putative regulatory role in autophagy, future studies may consider DAXX as a candidate marker and therapeutic target for prostate cancer.
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Affiliation(s)
- Lorena A Puto
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Christopher Benner
- Integrative Genomics and Bioinformatics Core, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Tony Hunter
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
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Abstract
Imbalanced cell death is a common phenomenon in many human diseases, including cancer. DAPK's essential function is in promoting apoptosis. DAPK interacts with stress-induced receptors through its death domain to initiate an apoptosis cascade. In addition, DAPK phosphorylates multiple cytosolic substrates and can mediate transfer of signaling pathways to the effector caspases. A series of studies demonstrated that, depending on stimuli, DAPK expression is regulated on both the transcriptional and posttranscriptional levels. Silencing of DAPK due to hypermethylation of its promoter was reported in many types of cancer. STAT3 and p52-NFkB transcription factors have been shown to down-regulate DAPK expression. In contrast, p53, C/EBP-β and Smad transcription factors bind to their specific response elements within the DAPK promoter and induce its transcription. Post-transcriptionally, DAPK undergoes alternative splicing, which results in the production of two functionally different isoforms. Moreover, miRNA 103 and miRNA 107 recently were shown to inhibit DAPK in colorectal cancer. Here we summarize our recent knowledge about transcriptional regulation of DAPK expression.
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Affiliation(s)
- Natalya Benderska
- Experimental Tumorpathology, Institute of Pathology, Friedrich-Alexander- University of Erlangen-Nuremberg, Universitätstrasse 22, 91054, Erlangen, Germany
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IKK phosphorylates RelB to modulate its promoter specificity and promote fibroblast migration downstream of TNF receptors. Proc Natl Acad Sci U S A 2014; 111:14794-9. [PMID: 25267645 DOI: 10.1073/pnas.1410124111] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
TNFα is a potent cytokine that plays a critical role in numerous cellular processes, particularly immune and inflammatory responses, programmed cell death, angiogenesis, and cell migration. Thus, understanding the molecular mechanisms that mediate TNFα-induced cellular responses is a crucial issue. It is generally accepted that global DNA binding activity of the NF-κB avian reticuloendotheliosis viral (v-rel) oncogene related B (RelB) subunit is not induced upon TNFα treatment in fibroblasts, despite its TNFα-induced nuclear accumulation. Here, we demonstrate that RelB plays a critical role in promoting fibroblast migration upon prolonged TNFα treatment. We identified the two kinases IκB kinase α (IKKα) and IκB kinase β (IKKβ) as RelB interacting partners whose activation by TNFα promotes RelB phosphorylation at serine 472. Once phosphorylated on serine 472, nuclear RelB dissociates from its interaction with the inhibitory protein IκBα and binds to the promoter of critical migration-associated genes, such as the matrix metallopeptidase 3 (MMP3). Further, we show that RelB serine 472 phosphorylation status controls MMP3 expression and promigration activity downstream of TNF receptors. Our findings provide new insights into the regulation of RelB activity and reveal a novel link between selective NF-κB target gene expression and cellular response in response to TNFα.
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Leidner J, Voogdt C, Niedenthal R, Möller P, Marienfeld U, Marienfeld RB. SUMOylation Attenuates the Transcriptional Activity of the NF-κB Subunit RelB. J Cell Biochem 2014; 115:1430-40. [DOI: 10.1002/jcb.24794] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 02/20/2014] [Indexed: 12/22/2022]
Affiliation(s)
- Julia Leidner
- Institute of Physiological Chemistry; University of Ulm; Albert-Einstein-Allee 23 89070 Ulm Germany
| | - Cornelia Voogdt
- Institute of Pathology; University of Ulm; Albert-Einstein-Allee 23 89070 Ulm Germany
| | - Rainer Niedenthal
- Institute for Physiological Chemistry/Biochemistry; Hannover Medical School; Carl-Neuberg Strasse 1 30625 Hannover Germany
| | - Peter Möller
- Institute of Pathology; University of Ulm; Albert-Einstein-Allee 23 89070 Ulm Germany
| | - Uta Marienfeld
- Institute of Pathology; University of Ulm; Albert-Einstein-Allee 23 89070 Ulm Germany
| | - Ralf B. Marienfeld
- Institute of Pathology; University of Ulm; Albert-Einstein-Allee 23 89070 Ulm Germany
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Disclosing the crosstalk among DNA methylation, transcription factors, and histone marks in human pluripotent cells through discovery of DNA methylation motifs. Genome Res 2013; 23:2013-29. [PMID: 24149073 PMCID: PMC3847772 DOI: 10.1101/gr.155960.113] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Gene expression regulation is gated by promoter methylation states modulating transcription factor binding. The known DNA methylation/unmethylation mechanisms are sequence unspecific, but different cells with the same genome have different methylomes. Thus, additional processes bringing specificity to the methylation/unmethylation mechanisms are required. Searching for such processes, we demonstrated that CpG methylation states are influenced by the sequence context surrounding the CpGs. We used such a property to develop a CpG methylation motif discovery algorithm. The newly discovered motifs reveal “methylation/unmethylation factors” that could recruit the “methylation/unmethylation machinery” to the loci specified by the motifs. Our methylation motif discovery algorithm provides a synergistic approach to the differently methylated region algorithms. Since our algorithm searches for commonly methylated regions inside the same sample, it requires only a single sample to operate. The motifs that were found discriminate between hypomethylated and hypermethylated regions. The hypomethylation-associated motifs have a high CG content, their targets appear in conserved regions near transcription start sites, they tend to co-occur within transcription factor binding sites, they are involved in breaking the H3K4me3/H3K27me3 bivalent balance, and they transit the enhancers from repressive H3K27me3 to active H3K27ac during ES cell differentiation. The new methylation motifs characterize the pluripotent state shared between ES and iPS cells. Additionally, we found a collection of motifs associated with the somatic memory inherited by the iPS from the initial fibroblast cells, thus revealing the existence of epigenetic somatic memory on a fine methylation scale.
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Abstract
This review highlights recent discoveries that have shaped the emerging viewpoints in the field of epigenetic influences in the central nervous system (CNS), focusing on the following questions: (i) How is the CNS shaped during development when precursor cells transition into morphologically and molecularly distinct cell types, and is this event driven by epigenetic alterations?; ii) How do epigenetic pathways control CNS function?; (iii) What happens to "epigenetic memory" during aging processes, and do these alterations cause CNS dysfunction?; (iv) Can one restore normal CNS function by manipulating the epigenome using pharmacologic agents, and will this ameliorate aging-related neurodegeneration? These and other still unanswered questions remain critical to understanding the impact of multifaceted epigenetic machinery on the age-related dysfunction of CNS.
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Affiliation(s)
- Yue-Qiang Zhao
- />Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA 94945-1400 USA
- />Department of Plastic Surgery, Renmin Hospital of Wuhan University, Wuhan, China
| | - I. King Jordan
- />School of Biology, Georgia Institute of Technology, Atlanta, GA USA
- />PanAmerican Bioinformatics Institute, Santa Marta, Magdalena Colombia
| | - Victoria V. Lunyak
- />Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA 94945-1400 USA
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Izumiya Y, Kobayashi K, Kim KY, Pochampalli M, Izumiya C, Shevchenko B, Wang DH, Huerta SB, Martinez A, Campbell M, Kung HJ. Kaposi's sarcoma-associated herpesvirus K-Rta exhibits SUMO-targeting ubiquitin ligase (STUbL) like activity and is essential for viral reactivation. PLoS Pathog 2013; 9:e1003506. [PMID: 23990779 PMCID: PMC3749962 DOI: 10.1371/journal.ppat.1003506] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 06/03/2013] [Indexed: 01/26/2023] Open
Abstract
The small ubiquitin-like modifier (SUMO) is a protein that regulates a wide variety of cellular processes by covalent attachment of SUMO moieties to a diverse array of target proteins. Sumoylation also plays an important role in the replication of many viruses. Previously, we showed that Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a SUMO-ligase, K-bZIP, which catalyzes sumoylation of host and viral proteins. We report here that this virus also encodes a gene that functions as a SUMO-targeting ubiquitin-ligase (STUbL) which preferentially targets sumoylated proteins for degradation. K-Rta, the major transcriptional factor which turns on the entire lytic cycle, was recently found to have ubiquitin ligase activity toward a selected set of substrates. We show in this study that K-Rta contains multiple SIMs (SUMO interacting motif) and binds SUMOs with higher affinity toward SUMO-multimers. Like RNF4, the prototypic cellular STUbL, K-Rta degrades SUMO-2/3 and SUMO-2/3 modified proteins, including promyelocytic leukemia (PML) and K-bZIP. PML-NBs (nuclear bodies) or ND-10 are storage warehouses for sumoylated proteins, which negatively regulate herpesvirus infection, as part of the intrinsic immune response. Herpesviruses have evolved different ways to degrade or disperse PML bodies, and KSHV utilizes K-Rta to inhibit PML-NBs formation. This process depends on K-Rta's ability to bind SUMO, as a K-Rta SIM mutant does not effectively degrade PML. Mutations in the K-Rta Ring finger-like domain or SIM significantly inhibited K-Rta transactivation activity in reporter assays and in the course of viral reactivation. Finally, KSHV with a mutation in the Ring finger-like domain or SIM of K-Rta replicates poorly in culture, indicating that reducing SUMO-conjugates in host cells is important for viral replication. To our knowledge, this is the first virus which encodes both a SUMO ligase and a SUMO-targeting ubiquitin ligase that together may generate unique gene regulatory programs.
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Affiliation(s)
- Yoshihiro Izumiya
- Department of Dermatology, University of California Davis (UC Davis) School of Medicine, UC Davis Comprehensive Cancer Center, Sacramento, California, United States of America
- Department of Biological Chemistry and Molecular Medicine, UC Davis School of Medicine, UC Davis Comprehensive Cancer Center, Sacramento, California, United States of America
- * E-mail: (YI); (HJK)
| | - Keisuke Kobayashi
- Department of Dermatology, University of California Davis (UC Davis) School of Medicine, UC Davis Comprehensive Cancer Center, Sacramento, California, United States of America
- Department of Basic Pathology, National Defense Medical College, Namiki, Tokorozawa, Saitama, Japan
| | - Kevin Y. Kim
- Department of Dermatology, University of California Davis (UC Davis) School of Medicine, UC Davis Comprehensive Cancer Center, Sacramento, California, United States of America
| | - Mamata Pochampalli
- Department of Biological Chemistry and Molecular Medicine, UC Davis School of Medicine, UC Davis Comprehensive Cancer Center, Sacramento, California, United States of America
| | - Chie Izumiya
- Department of Biological Chemistry and Molecular Medicine, UC Davis School of Medicine, UC Davis Comprehensive Cancer Center, Sacramento, California, United States of America
| | - Bogdan Shevchenko
- Department of Dermatology, University of California Davis (UC Davis) School of Medicine, UC Davis Comprehensive Cancer Center, Sacramento, California, United States of America
| | - Don-Hong Wang
- Department of Dermatology, University of California Davis (UC Davis) School of Medicine, UC Davis Comprehensive Cancer Center, Sacramento, California, United States of America
| | - Steve B. Huerta
- Department of Dermatology, University of California Davis (UC Davis) School of Medicine, UC Davis Comprehensive Cancer Center, Sacramento, California, United States of America
| | - Anthony Martinez
- Department of Biological Chemistry and Molecular Medicine, UC Davis School of Medicine, UC Davis Comprehensive Cancer Center, Sacramento, California, United States of America
| | - Mel Campbell
- Department of Dermatology, University of California Davis (UC Davis) School of Medicine, UC Davis Comprehensive Cancer Center, Sacramento, California, United States of America
| | - Hsing-Jien Kung
- Department of Biological Chemistry and Molecular Medicine, UC Davis School of Medicine, UC Davis Comprehensive Cancer Center, Sacramento, California, United States of America
- National Health Research Institutes, Taipei, Taiwan
- * E-mail: (YI); (HJK)
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DNA methylation and apoptosis resistance in cancer cells. Cells 2013; 2:545-73. [PMID: 24709797 PMCID: PMC3972670 DOI: 10.3390/cells2030545] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2013] [Revised: 06/27/2013] [Accepted: 06/28/2013] [Indexed: 01/13/2023] Open
Abstract
Apoptosis is a cell death programme primordial to cellular homeostasis efficiency. This normal cell suicide program is the result of the activation of a cascade of events in response to death stimuli. Apoptosis occurs in normal cells to maintain a balance between cell proliferation and cell death. A deregulation of this balance due to modifications in the apoptosic pathway leads to different human diseases including cancers. Apoptosis resistance is one of the most important hallmarks of cancer and some new therapeutical strategies focus on inducing cell death in cancer cells. Nevertheless, cancer cells are resistant to treatment inducing cell death because of different mechanisms, such as DNA mutations in gene coding for pro-apoptotic proteins, increased expression of anti-apoptotic proteins and/or pro-survival signals, or pro-apoptic gene silencing mediated by DNA hypermethylation. In this context, aberrant DNA methylation patterns, hypermethylation and hypomethylation of gene coding for proteins implicated in apoptotic pathways are possible causes of cancer cell resistance. This review highlights the role of DNA methylation of apoptosis-related genes in cancer cell resistance.
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Zizzi A, Montironi MA, Mazzucchelli R, Scarpelli M, Lopez-Beltran A, Cheng L, Paone N, Castellini P, Montironi R. Immunohistochemical analysis of chromatin remodeler DAXX in high grade urothelial carcinoma. Diagn Pathol 2013; 8:111. [PMID: 23819605 PMCID: PMC3751668 DOI: 10.1186/1746-1596-8-111] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Accepted: 06/25/2013] [Indexed: 01/06/2023] Open
Abstract
Background/Aims The chromatin remodeler DAXX, a predominantly nuclear protein, regulates the status of chromatin organization. The aim of this exploratory immunohistochemical study was to evaluate DAXX protein expression in high grade invasive urothelial carcinoma (UC) of the bladder as a biological regulator of aggressiveness. Methods Quantitative analysis was made on DAXX immunostained nuclei in tissue sections from 5 cases of bladder normal urothelium (NU) and 5 cases of bladder pT1 UC. Carcinoma in situ (CIS) and high grade papillary carcinoma (HGPCa) were identified in 2 out of 5 UC cases. Results The nuclei in UC show an open configuration of the chromatin composed of granules varying in size and distribution and a mean nuclear area 1.7 times greater than that in NU (UC: mean and SD 24.4 ± 11.4 square microns; NU: 14.8 6.5 square microns. The differences are statistically significant). 70% of the NU nuclei are immunostained, whereas 90% of UC nuclei are positive. The mean gray level value in UC, related to the intensity of nuclear immunostaining, is lower than in NU by a factor of 0.94 (UC: mean and SD 100 ± 15; NU: 106 ± 15. The differences are statistically significant). In particular, the value in the nuclei adjacent to the stroma in UC is slightly lower than in the intermediate cell layers by factor of 0.98, whereas in NU it is slightly greater by a factor 1.02 and 1.04 compared to the intermediate and superficial cell layers. The values in CIS and HGPCa are similar to those in UC. Conclusions The quantitative immunohistochemical analysis shows an altered protein expression of chromatin remodeler DAXX in UC and in its preinvasive phases, when compared to NU. DAXX evaluation, if associated with markers related to global DNA methylation and histone acetylation, could be used in clinical practice as a marker of aggressiveness. Virtual slides The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1398457297102379
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Affiliation(s)
- Antonio Zizzi
- Section of Pathological Anatomy, Polytechnic University of the Marche Region, School of Medicine, United Hospitals, Via Conca 71, 60126, Torrette Ancona, Italy
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Salomoni P. The PML-Interacting Protein DAXX: Histone Loading Gets into the Picture. Front Oncol 2013; 3:152. [PMID: 23760585 PMCID: PMC3675705 DOI: 10.3389/fonc.2013.00152] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 05/24/2013] [Indexed: 12/23/2022] Open
Abstract
The promyelocytic leukemia (PML) protein has been implicated in regulation of multiple key cellular functions, from transcription to calcium homeostasis. PML pleiotropic role is in part related to its ability to localize to both the nucleus and cytoplasm. In the nucleus, PML is known to regulate gene transcription, a role linked to its ability to associate with transcription factors as well as chromatin-remodelers. A new twist came from the discovery that the PML-interacting protein death-associated protein 6 (DAXX) acts as chaperone for the histone H3.3 variant. H3.3 is found enriched at active genes, centromeric heterochromatin, and telomeres, and has been proposed to act as important carrier of epigenetic information. Our recent work has implicated DAXX in regulation of H3.3 loading and transcription in the central nervous system (CNS). Remarkably, driver mutations in H3.3 and/or its loading machinery have been identified in brain cancer, thus suggesting a role for altered H3.3 function/deposition in CNS tumorigenesis. Aberrant H3.3 deposition may also play a role in leukemia pathogenesis, given DAXX role in PML-RARα-driven transformation and the identification of a DAXX missense mutation in acute myeloid leukemia. This review aims to critically discuss the existing literature and propose new avenues for investigation.
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Affiliation(s)
- Paolo Salomoni
- Samantha Dickson Brain Cancer Unit, UCL Cancer Institute , University College London, London , UK
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Halder UC, Bhowmick R, Roy Mukherjee T, Nayak MK, Chawla-Sarkar M. Phosphorylation drives an apoptotic protein to activate antiapoptotic genes: paradigm of influenza A matrix 1 protein function. J Biol Chem 2013; 288:14554-14568. [PMID: 23548901 DOI: 10.1074/jbc.m112.447086] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
During infection, viral proteins target cellular pathways that regulate cellular innate immune responses and cell death. We demonstrate that influenza A virus matrix 1 protein (M1), an established proapoptotic protein, activates nuclear factor-κB member RelB-mediated survival genes (cIAP1, cIAP2, and cFLIP), a function that is linked with its nuclear translocation during early infection. Death domain-associated protein 6 (Daxx) is a transcription co-repressor of the RelB-responsive gene promoters. During influenza virus infection M1 binds to and stabilizes Daxx protein by preventing its ubiquitination and proteasomal degradation. Binding of M1 with Daxx through its Daxx binding motif prevents binding of RelB and Daxx, resulting in up-regulation of survival genes. This interaction also prevents promoter recruitment of DNA methyltransferases (Dnmt1 and Dnmt3a) and lowers CpG methylation of the survival gene promoters, leading to the activation of these genes. Thus, M1 prevents repressional function of Daxx during infection, thereby exerting a survival role. In addition to its nuclear localization signal, translocation of M1 to the nucleus depends on cellular kinase-mediated phosphorylation as the protein kinase C inhibitor calphostin C effectively down-regulates virus replication. The study reconciles the ambiguity of dual antagonistic function of viral protein and potentiates a possible target to limit virus infection.
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Affiliation(s)
- Umesh Chandra Halder
- Division of Virology, National Institute of Cholera and Enteric Diseases, P-33 C.I.T. Road, Scheme-XM, Beliaghata, Kolkata 700010, India
| | - Rahul Bhowmick
- Division of Virology, National Institute of Cholera and Enteric Diseases, P-33 C.I.T. Road, Scheme-XM, Beliaghata, Kolkata 700010, India
| | - Tapasi Roy Mukherjee
- Division of Virology, National Institute of Cholera and Enteric Diseases, P-33 C.I.T. Road, Scheme-XM, Beliaghata, Kolkata 700010, India
| | - Mukti Kant Nayak
- Department of Zoology, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, India
| | - Mamta Chawla-Sarkar
- Division of Virology, National Institute of Cholera and Enteric Diseases, P-33 C.I.T. Road, Scheme-XM, Beliaghata, Kolkata 700010, India.
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Vu D, Huang DB, Vemu A, Ghosh G. A structural basis for selective dimerization by NF-κB RelB. J Mol Biol 2013; 425:1934-1945. [PMID: 23485337 DOI: 10.1016/j.jmb.2013.02.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 02/14/2013] [Accepted: 02/15/2013] [Indexed: 11/19/2022]
Abstract
Transcription factors of the nuclear factor kappaB (NF-κB) family arise through the combinatorial association of five distinct Rel subunits into functional dimers. However, not every dimer combination is observed in cells. The RelB subunit, for example, does not appear as a homodimer and forms heterodimers exclusively in combination with p50 or p52 subunits. We previously reported that the RelB homodimer could be forced to assemble through domain swapping in vitro. In order to understand the mechanism of selective dimerization among Rel subunits, we have determined the x-ray crystal structures of five RelB dimers. We find that RelB forms canonical side-by-side heterodimers with p50 and p52. We observe that, although mutation of four surface hydrophobic residues that are unique to RelB does not affect its propensity to form homodimers via domain swapping, alteration of two interfacial residues converts RelB to a side-by-side homodimer. Surprisingly, these mutant RelB homodimers remain distinct from canonical side-by-side NF-κB dimers in that the two monomers move away from one another along the 2-fold axis to avoid non-complementary interactions at the interface. The presence of distinct residues buried within the hydrophobic core of the RelB dimerization domain appears to influence the conformations of the surface residues that mediate the dimer interface. This conclusion is consistent with prior observations that alterations of domain core residues change dimerization propensity in the NF-κB family transcription factors. We suggest that RelB has evolved into a specialized NF-κB subunit with unique amino acids optimized for selective formation of heterodimers with p50 and p52.
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Affiliation(s)
- Don Vu
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0375, USA
| | - De-Bin Huang
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0375, USA
| | - Annapurna Vemu
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0375, USA
| | - Gourisankar Ghosh
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0375, USA.
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